Boring-tool.



E. E. DAVIS.

BORING TOOL. APPLICATION FILED 'JULY 10, 1911.

' '1,078,1 1 m Patented N0v. 18, 1913.

l, TATES liFIClht.

EMERY E. DAVIS. 01 ST. LOUIS. MISSUURL ASSIGETOR T0 MATTHEWS-DAVIS TOOL CGIMPANY, U3? GT.LOU1E3, MISSOURI, A (JORPURATION OF MISSOURI.

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Original application filed December 16, 1910, Sena! 1911. Serial To all whom it may can own.

Beitknown that l, lhuuar l l. Hairs, a citizen of the United States, residing at St. Louis, Missouri, have\invcnted. a certain new and useful Improvement in l-loring-Tools, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to whiel'i it appertains to make and use the same, reference being had to the accompanying drawings, fm'ming); part of this specification, in Wliich--- lii rurc 1 is a perspective View of a boring tool of my ii'nprorcd coi'istruction. Fig. 2 is a. section through the center of the forward end of the tool, and taken approximately on the line .2----Q of Fig. 1. Fig. 3 is a horirontal section taken on the line S-3 of Fig. 2. hie". is a perspective view of one of the nib carrying blocks utilized for clampin g'and locking; the cutters or bits in the head of my imprm'ed boring: tool.

My invention relates to an expansion boring tool of the type shown and described in the patent issued to me October 24-, 1905 No. 802,737, and my 'nesenl'. application is a division of a. eo-pcnding application for in-.-. provements in boring tools filed by me De cember 1(3, 1910, Serial No. 597,687.

In the patent and application just referred to I disclosed constructions utilizing only one pair of bits or cutters, and it is the object of my present invention to provide a boring tool having a plurality of pairs of bits or cutters, one pair of cutters being used for making the first or rough out, and the second. set of bits being" utilized for producing the linisl'iinp, or smooth cut.

A. further object of my invention to provide self adjusting gibs which eruragre the bits or cutle'rs for the purpose of locking them in operative position within the head or body of the tool, and further to pro vide means for forcing the self adjusting gibs into close Contact with the bits or cut ters.

My invention consists in certain features of novelty and arrangement of parts hereinafter more fully described and claimed.

Referring) by numerals to the accompany ing' drawing... 1. designates the body of my improved bonn e,- tool, which is in cylindrical form and is removably mounted in any suitable manner-upon one end of a shank or rod 2'. Formed through the body 1 at a Specification of Letters Patent.

Patented um. 18, i em.

adjustine means, preferably such ailjusting means as is shown in my Patent #802,737, hereinbefmrc referred to, or in Patent t1,( l(i.T-10. issued to roe-December 10,1912. Park; of this bit adjusting means are shown in section in Fig. 2.

designates the bits or cutters which are located in the slot 3 and this pair of cut. tors consdructed especially for rough botion. The outer ends ofi.,these cutters are provided with notches orrecesses (5 which perl'nit the chips or shavings removed by the cutters to curl parallel with the body of the tool, which action permits the tool to be operated easily and with comparatively lit tle power.

'lhe pair of cutters 7 located in the slot -'l are especially constructed for making a finishingor emoolh cut, and the outer corners of this pair ctr-utters are rounded off as ale-- signated by 8 so as to bore a perfectly smooth hole during operations Fro-med in the face of the body 1 immediately in front of the projecting ends of the cutters (3 and 8 are recesses or pockets 9 which are for the purpose of reciziving the chips and shavings removed by the cuttors during operation, and these pockets alm serve as a. reservoir for the lubricant used on the tool while the same is in operation.

The means employed for locking the bits or cutters in position within the body of the tool comprises a block 10 in the top of which is fin-med a pair of pockets 11, the bottoms of which are curved lengthwise and mounted in each pocket is a gib 12, the under side of which is curved to conform to the curvzc 100 ture of the bottom of the pocket, and the top face of'which gib is flat and adapted to can gage against the corresponding face on the under side of the. adjacent bit or cutter.

l0 dcsignati-is pins, the ends of which are are slightly larger in diameter than are said pins. lhis construction permits each gib 12 to have a slight vertical movement, and also a slight rocking movement independent of the-block l0, and thus when the gibs are brought into engagement with the under sides of the bits or cutters said gibs will independently adjust themselves to the surface with which they contact. Such construction also prevents the gibs from dropping out of the blocks 10 when the same are removed from the body of the tool. One of these gib carrying blocks is located beneath each pair of bits or cutters and the block located below the pair of cutters 5 is forced upwardly to lock said cutters 5 to the body 1 by means of a screw 13, which passes through the end of the body 1, and bears against the under side of the central portion of said block- 10. The gib carrying block located in the slot 4 beneath the pair of bits or cutters 7 is forced upward to lock said bits or cutters 7 in position by means of a screw 14 which is seated in a transversely disposed aperture 15 immediately below the slot 4,'and the central'portion or" which screw is tapered as designated by 16, said tapered portion bearing against the under side of this gib carrying block.

It will be noted that the gibs 12 are independently mounted in the gib carrying block, and therefore, when the blocks carrying said gibs are moved toward the cutters, said gibs will automatically adjust themselves to the corresponding faces of the bits or cutters. Thus each bit or cutter is individually engaged by a self adjusting gib and when the screws 13 and 14 are tightened the bits or cutters will be very firmly locked to the body of the tool.

A boring tool of my improved construction is comparatively simple, can be operated with little power and the rough cutting and smooth boring operations, which usually require two tools and two distinct operations are accomplished with the one tool and by a single operation.

It will be readily understood that minor changes in the size, and construction of the various parts of my improved device may be made and substituted for those herein shown and described without departing from the spirit of my invention, the scope of which. is set forth in the appended claim.

I claim:

In a boring tool, a slotted body, a pair of cutters adjustably positioned in the slot in said body, a block positioned in the slot below said cutters, which block is provided in its top with a. pair of recesses having curved bottoms, gibs mounted in said recesses, which gibs have curved under faces adapted to en-' gage the curved-bottoms of the recesses, and which gibs project a substantial distance beyond the face of the block so as to engage the undersides of the cutters independently of said block, said gibs being provided with transverse apertures, pins having their ends seated in the block to the sides of the recesses therein, which pins pass through the apertures in the gibs, said apertures being substantially larger in diameter than said pins, and a screw seated in the body and bearing against the underside of the block for forcing the same toward the cutters to cause the outer faces of the gibs to engage the adjacentfaces of the cutters.

In testimony whereof I hereunto afiix my signaturein the presence of two witnesses, this 5th day of July, 1911.

EMERY E. DAVIS. lVitnesses:

' M. P. SMITH, B. S. REID. 

